Carl Conyers was interviewed by Houston police investigators and is with family, Smith said. The circumstances of his disappearance are under investigation. He had been the subject of a search since Tuesday, when he was last seen by his roommate.

"Rep. Conyers has been in touch with his family and is happy his son is safe and uninjured," Shadawn Reddick-Smith, a spokeswoman for John Conyers, said in a statement.

Carl Conyers' girlfriend, Daisha Lewis, told WWJ-AM in Detroit she was supposed to meet him on campus Wednesday, but he never showed. When she and friends checked his apartment they found some clothes and other items missing.

Houston police spokesman Kese Smith earlier said the department was working with the FBI and Secret Service to find the missing student. Smith said the Secret Service was involved because Carl Conyers is the son of a congressman.

Conyers, whose Michigan district includes parts of Detroit, is the longest-serving member of the House and is the first black person to hold that distinction. He was first elected in 1964. His wife, Monica, is in Texas awaiting any developments in the search.

Carl Conyers' roommate, Chet Ball, suggested Conyers may have been overwhelmed by his studies.

"School can be hard on a person," Ball told reporters outside of their apartment. "Stress is very serious."

Corey Gentry, a friend and schoolmate of Conyers, told the Houston Chronicle that Conyers is active on campus, as president of the school's Black Business Students Association and a member of an arts group called Uncommon Colors.